.slide{
    width: 500px;
    height: 300px;
    margin: 50px auto;
    position: relative;
}

.slide img{
    width: 100%;
    height: 300px;
}

.slide .btn{
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(0, 0, 0, .3);
    position: absolute;
    top: 40%;
    color: white;
    line-height: 50px;
    text-align: center;
    font-size: 25px;
    cursor: pointer;
}

.slide .prev{
    left: 10px;
}

.slide .next{
    right: 10px;
}